Patrick Horn, MD, PhD, Chief Medical Officer at HemoShear Therapeutics, gives an overview of methylmalonic acidemia (MMA) and propionic acidemia (PA). 

As Dr. Horn explains, MMA and PA are rare inherited metabolic disorders in which the body is unable to process certain proteins and lipids properly. MMA is characterized by deficiency of methylmalonyl-CoA mutase, while PA is characterized by deficiency of propionyl-CoA carboxylase. These enzymes are directly involved in the breakdown of amino acids as well as cholesterol, certain fatty acids, and other substances necessary for metabolic processes. The deficiency of these enzymes leads to accumulation of these chemicals and metabolites which harms the mitochondria. Symptoms of these disorders are usually apparent during the first weeks of life and may include hypotonia, poor feeding, vomiting, failure to thrive, lethargy, dehydration and seizures. Without appropriate treatment, coma and death may result. Rarely, the condition may become apparent later in life and may be associated with less severe symptoms and findings. MMA and PA patients have to follow a specific diet including a low protein intake and specific food formulas. Liver transplant to decrease the frequency of acute metabolic episodes is also an option. 

Dr. Horn also notes that MMA and PA are diagnosed through newborn screening. However, in more severe cases, patients are already in metabolic crisis by the time the results of the newborn screening are given to the parents.

To learn more about MMA, PA, and other metabolic disorders, visit https://checkrare.com/diseases/metabolic-disorders/ 

To learn more about newborn screening for metabolic conditions, visit our CME program on this subject at checkrare.com/learning/p-newborn-screening-metabolic-conditions/